Abstract: Crowding is defined as the deleterious influence of nearby stimulus on visual discrimination. Most researchers suggested that crowding occurred at the level of feature processing, and was caused by the erroneous combination of signals from the targets and the flankers. Many feature-based processing mechanisms have been proposed to account for the crowding effect, involving feature integration, centroid account, compulsory averaging and some quantitative models. However, there was no strong empirical evidence for these mechanisms. Future research should combine the ERP technology and use a variety of stimulus (e.g. moving stimulus, etc) to investigate the mechanisms of spatial and temporal crowding.

Key words: crowding effect, feature integration model, centroid model, compulsory averaging model